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How to de-ice your sidewalk and drive without de-foresting your lawn

December 17, 2014

By Pam Leibfried

After last winter’s polar vortex deep freeze, many homeowners found brown, damaged landscaping when the snow thawed in the spring. Much of the damage was caused by the use of rock salt to melt ice on paved areas around your home. Obviously, not de-icing your sidewalk and driveway is not a good – or safe – option, so here are some tips on how to de-ice while minimizing damage to your landscaping.

A good shovel is your best defense
One of the most effective tactics to keep your sidewalk and driveway ice-free – thus reducing the need for plant-damaging de-icers – is to shovel snow thoroughly, as soon as possible after the snow stops falling. By minimizing the accumulation of packed snow, you lessen the amount of water that accumulates when it gets warm enough for that snow to melt. The thawed snow, if left on the pavement, will generally re-freeze as a sheet of ice when it gets cold again. Shoveling can’t stop ice from accumulating if your area is experiencing sleet or freezing rain, but it is vital to help minimize the process of snow getting packed down by footsteps and vehicles, then melting and refreezing into a mini ice rink.

De-icing products
There are many brands of commercially available de-icers, some of which combine multiple types of de-icing chemicals in one product. We can’t cover them all here, so we’ll review just the most commonly used types of basic deicers.

  • Sodium Chloride. Although its chemical name is sodium chloride, rock salt is the name most commonly used on packaging in stores. It is the most widely used de-icer because it is generally the cheapest. It can be bad for pets if they lick the salt and it is harmful to grass and other plants. Rock salt leaves a white residue on paws and shoes – and thus, unfortunately, on floors and rugs. Also, it only works at temperatures above 20° F.
  • Magnesium Chloride. It de-ices at lower temperatures than rock salt (down to -5° F). Although it is considered to be safer than rock salt or calcium chloride in terms of its environmental impact, magnesium chloride has a higher concentration of chloride, making it more likely to cause pitting on the surface of concrete.
  • Calcium Chloride. More effective in extreme cold (down to -50° F), it gives off heat as it dissolves, making it one of the most fast-acting deicers. Used at the recommended rate, it not only doesn’t harm your plants, but can actually help them. It is safer for pets, who can be tempted to lick rock salt, making them sick. It is more expensive than rock salt, but some of that cost may be mitigated by reduced damage to vegetation.

The cost of de-icers can add up over the course of a winter, especially if you use the more expensive ones that are safer for your pets and lawn. So be sure that you watch for sales to avoid paying more to get your products the night before a predicted storm. And no matter which de-icer you use, read the directions on the package so you don’t over-apply it. In general, a handful of regular rock salt should be enough for a square yard of pavement. If you’re using calcium chloride, a handful will de-ice three times that area.

Heated driveways?
If you’re building a new home or are in the process of replacing old pavement, you may want to consider a heated driveway. They work on the same principle as radiant heat flooring, with a heating mechanism embedded just under the surface. The most typical installation involves a mat or grid of electric wires, sort of like a heating pad or electric blanket inside the concrete. The idea is to keep the temperature of the paved surface above freezing. Although these systems increase the cost of a driveway or sidewalk, they may be something you should consider, depending on your age, your ability to move snow or remove ice, and your general health. If you are elderly or have a medical condition that prevents you from removing the snow yourself, you may find the cost of a heated driveway is not unreasonable compared to the ongoing cost of paying a snow removal service to clear your driveway. And because it prevents ice from forming in the first place, a heated driveway can lessen the likelihood of injury from falls on slippery surfaces.

Mitigating damage that’s already done
If the winter is particularly icy and you end up using an amount of de-icer salt that makes you concerned about damage to your lawn or plants, there are ways to mitigate that damage. If you can, remove ice and snow from areas bordering pavement as soon as it begins to melt in the spring, before everything is melted and all the de-icer penetrates the soil. After the ground has thawed, water the affected area with the equivalent of 1-2 inches of rain over a several-hour period. A few days later, water it again, then sprinkle the affected soil with gypsum to help reduce the level of salt in the soil. For details and other tips, refer to the Landscape Damage section of our polar vortex article from the April 2014 issue of Alliant Home Advisor.